Ceramic is a generic term for non-metallic inorganic materials such as oxides, nitrides, carbides, etc., composed primarily of inorganic materials. Ceramics have excellent corrosion resistance, heat resistance, wear resistance, and the like, as compared with metal and organic materials, and are used in a variety of fields such as medical and health industry, chemistry, livestock industry, agriculture, fisheries, etc. Particularly, the ceramic material radiates far infrared light which is used for stabilizing and activating high molecular weight bio-structure through intensification of coupling of a water molecule to maintain freshness of food and accelerate a rate of chemical reaction such as fermentation. As such, ceramics are widely used in chemistry, livestock industry, agriculture, fisheries, and the like. In addition, ceramics have a porous structure which is known to have a function of adsorbing heavy metals and fungi in water through adsorption, absorption, and strain collection, and high hygroscopicity to provide functions of dehumidification, deodorization, anti-fungal activity, etc.
Ceramics are generally produced in the form of ceramic balls, which produce alkaline water having good and soft taste to drink, when used for water purification. Thus, the ceramic balls are used in a variety of fields for household, industry, agriculture and stockbreeding, such as water ionizers, filters for bidets, humidifiers, water purification and processing devices for washing, bathing, and the like, as well as water purifiers.
Various methods have been proposed to form ceramic powder into ceramic balls. For example, Korean Patent Laid-open Publication No. 1996-0012033 discloses spherical ceramic balls, which are formed using a compressing mould, Korean Patent Laid-open Publication No. 1996-0004277 discloses ceramic balls, which are formed by spraying a ceramic slurry in the form of droplets and sintering the droplets, and Korean Patent No. 153167 discloses spherical ceramic balls, which are formed by rotating/revolving a semi-sintered ceramic body in a rotary chamber composed of upper and lower halves.
However, these methods have problems in that it is difficult to form truly spherical ceramic balls, and there is a limit in achieving efficient production of a great quantity of ceramic balls within a short period of time.